Advances in Germplasm Resources of Chinese Milk Vetch in China

Chinese milk vetch( Astragalus sinicus L.) is a commonly used green manure crop in paddy fields in southern China and it has the effect of fostering fertility and soil. This paper firstly summarized advances in research of new high quality and yield varieties of germplasm resources of Chinese milk vetch. Then,on the basis of current situation,it came up with recommendations for collection,storage and promotion,as well as application in the current ecological agriculture,including establishing germplasm resource bank and improving germplasm resource evaluation system.

The effect of Pickering emulsion adjuvants on the immune efficacy of the COVID-19 polypeptide vaccine

Pickering emulsions were prepared by phacoemulsification in an ice water bath with squalene as the oil phase and an aluminum adjuvant as the particle stabilizer.The effects of formulation and process conditions on the size and distribution of the Pickering emulsions were investigated.Pickering emulsions prepared under the optimal prescription and process conditions were mixed with a peptide antigen to obtain a peptide vaccine.The optimal prescription and process condition of the Pickering emulsion is as follows:squalene as the oil phase,ultra-pure water as the water phase with 5 mg/mL aluminum adjuvant,and an ultrasonication time of 4 min at 200 W power.BALB/c mice were immunized with the peptide vaccine,and the ability of the Pickering emulsion as an immunological adjuvant to improve the efficacy of the peptide vaccine was evaluated.Under optimal conditions,a Pickering emulsion with a small particle size(430.8 nm),uniform distribution(polydispersion index of 16.9%),and zeta potential of 31.5 mV,was obtained.Immunological results showed that the serum specific antibody level in the vaccinated group reached 1×104 after three immunizations.The proportion of CD4+T cells and CD4/CD8 cells was significantly higher(P<0.05)in the vaccinated groups than the blank control group.Further,cytokine(TNF-𝛼)secretion decreased in the aluminum adjuvant and Pickering emulsion groups but increased in the Freund’s adjuvant group.All three vaccinated groups of mice exhibited low but detectable levels of IFN-𝛾secretion.

Novel sulfhydryl functionalized covalent organic frameworks for ultra-trace Hg^(2+) removal from aqueous solution

Two kinds of novel sulfhydryl functionalized covalent organic frameworks were fabricated as adsorbents for the removal of ultra-trace concentrations of Hg^(2+)from water.The two kinds of sulfhydryl functionalized covalent organic frameworks were obtained via a thiol-ene click reaction between the thiol groups of trithiocyanuric acid(TTC)or bismuththiol(BMT)and vinyl groups on the surface of covalent organic frameworks.The material structure was characterized by XRD,SEM,EDS,FT-IR,BET,and TG analysis.Due to their rich sulfur content,both adsorbents(COF-SH-1 and COF-SH-2)exhibited a high level of selective Hg^(2+)removal from aqueous solution with maximum adsorption capacities of 763.4 mg g^(-1) and526.3 mg g^(-1),respectively.Furthermore,in the presence of ultra-low concentrations of Hg^(2+)both materials exhibited excellent performance,achieving rapid Hg^(2+)removal at concentrations from 10μg L^(-1) to less than 0.02 ng L^(-1).Analysis of the adsorption mechanism indicates that the sulfur containing chelating groups exhibit a strong binding capacity for Hg^(2+).Results show that the structure determines the performance,with the amount of adsorption sites being related to the adsorption capacity.Therefore,as sulfhydryl functionalized covalent organic frameworks contain an abundance of adsorption sites,these materials can effectively achieve the removal of ultra-low trace Hg^(2+)concentrations and have promising future application potential for the environmental detection of heavy metals.